adj

• (pharmacology) Capable of soothing or eliminating pain.
  "Many a time has the vapor of ether been inhaled for the relief of oppressed lungs; many a time has the sought relief been thus obtained; and just so many times has the discovery of the wonderful anodyne properties of this gas, as affecting all bodily suffering, been brushed past and overlooked."
• (figuratively) Soothing or relaxing.
  "Classical music is rather anodyne."
• (by extension) Noncontentious, blandly agreeable, unlikely to cause offence or debate.
  "It all became so routine, so anodyne, so dull."

noun

• (pharmacology) Any medicine or other agent that relieves pain.
• (figuratively) A source of relaxation or comfort.
  "Nor do I mean to say that Virtue is not Virtue because it is never tempted to go astray; only that dulness is a much finer gift than we give it credit for being; and that some people are very lucky whom Nature has endowed with a good store of that great anodyne."